13 e-Letters

published between 2017 and 2020

  • A dog is not a standardised intervention

    Nice study, and great to see you including dog ownership in your COI statements! A plea from a veterinary surgeon interested in dog walking though: please collect and report data about the dogs. A dog isn't a standardised intervention like a Fitbit. Their exercise capacity and exercise desire will vary with breed, age, comorbidities, body condition score, behaviour yet no data about the dogs is included in this publication. In addition, research suggests that owning an ill or behaviourally problematic dog can be very stressful. These canine attributes may have introduced a level of unaccounted for heterogeneity into your intervention arm which may have confounded your results. I'd be happy to point any researchers in this field towards the relevant canine literature, or assist with dog aspects of a study design.

  • Conclusions questioned?

    Dear authors, I have read your paper with interest, and I have a couple of remarks that I think needs to be discussed to hopefully stimulate to more studies in this important field.
    It is a weakness that there are very few randomised trials on surgical treatment of tendinopathy. To then draw conclusions from few studies is difficult and not always possible.
    From this systematic review it is shown that 10 out 12 trials are on tendinopathy in the upper extremities (shoulder and elbow-althogether 998 tendinopathies) and only 2 on tendinopathy in the lower extremities (patellar and Achilles-althogeteher 60 tendinopathies). The authors have unfortunately missed to include 2 randomised studies on surgical treatment of patellar tendinopathy, published by Dr Willberg et al. Althogether, most information is about the shoulder and elbow, and very little about the Achilles and patellar tendons. Anyhow, when conclusions are drawn I get the impression that the authors put all tendinopathies in one group. This might be strongly misleading since there is very little information about the lower extremity tendons (only 2 studies), and conclusions cannot be drawn for Achilles and patellar tendinopathy. Furthermore, such conclusions might lead to that we miss possible differences in load response between upper and lower extremity tendons? The upper extremity non weight-bearing tendons might respond different compared to the lower extremity weight bearing tendons, as it is fo...

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  • Response to the viewpoint of Stöllberger and Finsterer: Side effects of and contraindication for whole body electromyostimulation

    In their recent viewpoint and article, Stöllberger and Finsterer 1 2 criticize the inadequate regulation of “whole body-electromyostimulation” (WB-EMS), potentially responsible for a variety of adverse effects recently reported. 3-6 Indeed, in contrast to locally applied EMS, the stimulation of all, or at least most, major muscle groups characterizes WB-EMS. Consequently, given that even locally applied EMS might cause severe rhabdomyolysis and hospitalization 7, it is obvious that a technology able to stimulate simultaneously up to 2600 cm2 of muscular area entails a much larger risk of triggering unintended side effects 3-6 at least when inadequately applied. 8
    Particularly with regard to the WB-EMS safety guidelines published in 2016 by our national WB-EMS consortium8, Stöllberger and Finsterer2 complain that the enquiring about contraindications and the requirements for a licensed WB-EMS trainer are not adequately specified. Overlapping with the publication of the article of Stöllberger and Finsterer, however it should be noted, that a German standard (DIN 33961-5, 9) was recently released which includes both contraindications for WB-EMS application in commercial, non-medical settings 10 and the requirements for the qualification of EMS trainers. Of importance, the latter was also specified by the 2019 revised German Radiation Protection Statutes (NiSV) a mandatory guideline published by the German “Bundesministerium für Umwelt, Naturschutz und nukleare Sicherhei...

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  • Longer career, longer follow up, immortality bias

    The article Mortality of Japanese Olympic athletes: 1952 – 2017 cohort study currently fails to account for a probable source of non-negligible bias. Whilst the main finding, stating that there is a decreased mortality rate among Japanese Olympians appears to be methodologically reliable, the authors also state that “higher mortality was observed among those who participated in the Olympics twice and three times or more compared with those who participated just once,” which we believe to be a potentially inaccurate finding.
    A delayed entry exists at baseline, as those with longer careers tend to be older than those with shorter careers. For instance, someone who has participated in 3 Olympic Games started her/his Olympic career 12 years before those who have participated only once. Thus, there might be an important period effect underlying these findings. Even if the authors have adjusted the analysis by age, this is not equivalent to adjusting for period, as earlier periods in time are related with higher mortality rates, which could explain the findings.
    Additionally, another problem often seen in survival studies is ignoring when a death event occurs. This is problematic because deaths will be observed more frequently in subjects with longer follow-up times. In the presence of time-dependent bias, the hazard ratio is artificially underestimated and the length bias leads to an artificial underestimation of the overall hazard [2]. Therefore, faulty interpretat...

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  • A holistic approach to lifestyle medicine training in medical students

    Dear Editor,

    We have read with interest the article by Radenkovic D et al. (1) As final year medical students having experienced both pre-clinical and clinical training, we agree that there is a significant gap in lifestyle medicine training. We appreciate the authors highlighting the gap in formal training and assessment of motivational interviewing. Evidence suggests there is a strong positive correlation in using motivational interviewing and the transtheoretical model of behaviour change as counselling strategies to achieve improved patient outcomes in lifestyle changes. (2)

    While this study focused primarily on physical exercise guidelines, it is important to define lifestyle medicine holistically, as it incorporates not only physical exercise but also nutrition, sleep, smoking as well as stress management. It would also be interesting to see how well trained medical students are in these other aspects of lifestyle medicine and how that correlates to lifestyle habits of students across various years of training. This could be done in the form or student welfare surveys throughout the academic year which would allow a more longitudinal holistic analysis of the representation of lifestyle medicine knowledge and student lifestyle habits. This can further inform targeted changes to medical school curriculum and student wellness interventions to ensure students are well equipped to maintain their own well-being and increase their confidence in counselling p...

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  • Stretching the conclusions a little too far?

    To the Editor,

    We read the recent publication by Nathan, Davies & Swaine (2018) with great interest due to a mutual interest in the subject of Generalised Joint Hypermobility (GJH) and its influence on injuries within elite sport. The authors of this paper should be commended for undertaking a study with such good participant numbers over a range of sports. We believe that the findings of this study suggesting that GJH may be protective of joint ligament damage may be a very important initial paper leading to valuable further exploration within specific sports and specific joints. However despite this good work we would like to take the opportunity to raise a concern over one of their conclusions and how this may confuse readers of the article.

    In the discussion section of this paper Nathan et al. (2018) suggest that the findings of this study may suggest that “regular stretching may increase flexibility, and this could subsequently reduce rates of injury in those that are less flexible.” We believe that this statement may lead to misunderstanding as the terms “flexibility” and “joint hypermobility” are two completely different entities.

    GJH is a hereditary physiological entity whereby most synovial joints move beyond their normal limits (Pacey et al., 2010) and may, or may not be symptomatic. This entity is commonly classified by the use of the Beighton Scale, as in the Nathan et al. (2018) paper, whereby adult participants are deemed positive i...

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  • Strong conclusions made on limited and inconsistent evidence

    To the Editor,

    We read with great interest the systematic review by Joschtel et al.1 on the effects exercise training on physical and psychological health in children with pediatric respiratory diseases such as asthma, bronchiectasis, bronchopulmonary dysplasia and cystic fibrosis (CF). Undoubtedly, the authors should be commended for their effort that they have put into this systematic review on an important research topic. However, we would like to take the opportunity to express some methodological concerns related to the CF studies included in this review.

    Joschtel et al.1 included studies on children, adolescents and young adults aged between 4 and 21 years and excluded those with a study population mean age of 21 years. These contradictory criteria have led to a false inclusion of one study 2 that included patients aged 12-40 years (although with a mean (SD) age of 19.5 (6.4) and 19.4 (5.3) for the intervention and control groups, respectively). Other studies 3 4, in which the mean age of the participants is <21 years were not considered for this review. Specifically, 3 out of 4 groups from the Kriemler et al. study 3 would qualify to be included in this review. Joschtel et al.1 did not publish a review protocol and therefore pre-specified inclusion and exclusion criteria cannot be verified.

    Joschtel et al.1 have conducted a meta-analysis on peak oxygen uptake (VO2peak), despite substantial heterogeneity of study characteristics (i.e., study...

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  • The Physical Inactivity Economic Cost and Burden Data in Developing Countries

    Thank you to the authors for emphasizing this topic. Physical inactivity remains the big problem and major pandemic in the world. Besides Sweden, many developing and developed countries have this serious problems. Researchers may suggest that physical inactivity cost lead to bigger healthcare cost and economic burden in the future. Physical inactivity is contributed to about 6-10% of ischaemic heart disease, stroke, diabetes, breast and colon cancer(1). Global physical inactivity cost is estimated $67.5 billions in total which consist direct cost around $53.8 billions and indirect cost around $13.7 billions (2). As for Europe and North America, it remains higher cost than in Asia. In China, the total cost of physical inactivity is estimated total about $6.7 billions (3). As for Korea, cost as much as 83.6 million was contributed to physical inactivity(4). While in North America and Europe, it remains high each $28.9 billions and $15.5 billions in total cost (2).

    It is much appreciated that the research filling the gap of data especially in Sweden. Other countries especially developing countries, should have the same idea about calculating the economic cost of physical inactivity. The current data in developing countries are inadequate, both direct and indirect cost which are very important. So that, the government can realize the important and dangerous effects of physical inactivity. Implementation should be underlined more on promotive and preventive action rath...

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  • The current evidence no longer supports the term “extreme conditioning programes;” let’s call it high-intensity functional training instead.

    Dear Editor in Chief:

    We read with great interest the recently published article by Tibana and de Sousa (1) titled “Are extreme conditioning programmes effective and safe? A narrative review of high intensity functional training methods research paradigms and findings.” We appreciate the opportunity to write this letter and hope to clarify some of the authors’ conclusions. Although the authors provide several examples of what they refer to as “extreme conditioning programs” we will focus mainly on the statements and evidence related to High Intensity Functional Training (HIFT), more commonly known as CrossFitTM training, as the authors’ review focuses primarily on this particular training program. We feel the authors have taken a biased position in describing this type of training and that their position is based on inaccurate and highly speculative interpretations of a fraction of the existing literature.

    Research examining the acute and long-term responses to HIFT, as well as the incidence of injury, is quite limited. The observed responses predominantly describe changes from baseline and in the case of long-term adaptations, generally show a positive outcome. Further, the few studies that make comparisons to other exercise forms only show select differences. More importantly, by the authors’ own admission, research examining the risk of injury do not suggest HIFT/CrossFitTM to be different from other forms of recreational exercise. Yet, the authors descri...

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  • Leucocyte Rich and Poor Platelet Concentrates and Tenocyte Proliferation

    We read with interest the article by Parrish et al, “Normal platelet function in platelet concentrates requires non-platelet cells: a comparative in vitro evaluation of leucocyte-rich (type 1a) and leucocyte-poor (type 3b) platelet concentrates.”(1)

    Parrish et al define PRP as a preparation with a platelet concentration of at least 5x over baseline, yet the LP-PRP they prepared (Arthrex Autologous Conditioned Plasma) was significantly lower at 2x over baseline, while the LR-PRP (Mitek Sports Medicine PEAK PRP) was significantly higher at 8x over baseline. We might reasonably expect that the ratio of growth factors between their LR-PRP and their LP-PRP to be approximately 8x/2x or 4:1, and this was indeed the case as seen in their Figure 4.

    Subsequently, the authors grew tenocytes (tendon cells) exposed to serum derived from LR-PRP and LP-PRP preparations. Given that their LR-PRP was approximately 4 times richer in growth factors than their LP-PRP, we might reasonably expect that the 2.5% solution of serum derived from their LR-PRP have approximately the same effect as the 10% solution of serum derived from their LP-PRP. However, their 10% LP-PRP solution actually resulted in higher growth of tenocytes (2656 light units) than their 2.5% LR-PRP solution (1001 light units), as seen in their Table 5, but not discussed by the authors. The fact that their 10% LR-PRP-derived serum caused tenocytes to grow to confluence while their 10% LP-PRP-derived serum did...

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